51. (     ) 

48. "Brain wave"machines may show (   ).

• A、the last one or two minutes of one's dream
  
  

• B、the story which lasts for hours or even days
  
  

• C、how long a dream lasts
  
  

• D、the explanations of one's dream
  
  

36. Taking cat naps (   ).

• A、will make a person lazy and tired 
  
  

• B、is a bad habit
  
  

• C、will make people feel better
  
  

• D、can help people become famous